High frequency jet ventilation has been used clinically in this unit for over 2 years. During this time we have treated 63 intensive care patients for whom the mean duration of ventilatory support was 3.4 days, which represents more than 5000 patient hours in total, with the Penlon Bromsgrove humidified jet ventilator. The series comprises a wide variety of general intensive care patients; a review of these cases is presented.